The present invention generally relates to an imaging device. More specifically, the present invention is directed to a handheld transillumination light source for locating and visualizing veins, arteries, and other subcutaneous structures of the body.
One of the first steps that a clinician takes in examining and diagnosing a patient is to visualize and palpate the area or structure of the patient's body to be examined. For example, when a clinician needs to perform an intravenous injection or extraction, he or she will often look for a vein seen from the surface of the skin or palpate the area to try and feel where a vein is located. If a vein cannot be seen or felt, a clinician may resort to using a tourniquet or asking the patient to pump his or her fist in hopes that veins will dilate and become visible. While this technique may be helpful in some instances, it still can be very difficult for a clinician to visualize and locate veins in patients with less prominent veins such as neonates, pediatric patients, obese patients, older adults, and patients with low blood pressure.
In these cases, transillumination has been a popular technique to assist the clinician in better visualizing and locating a patient's veins. Transillumination is a well-known imaging technique in which a sample is illuminated by the transmission of light through the sample. A clinician may use transillumination to illuminate a patient's arm, or other part of the patient's body from which fluid is to be injected or extracted. Because not as much light will penetrate through the patient's vasculature, the vasculature will appear darker and a clinician will have a visual of the patient's veins when inserting a needle for fluid injection or extraction.
A number of devices have been developed to allow a clinician to use the transillumination technique to visualize and locate the vasculature or any other subcutaneous structure in a patient. For example, U.S. Patent Application Publication No. 2005/0168980 to Dryden et al. discloses using one or more LEDs with predominant wavelengths between 600 and 640 nm. The LEDs are housed in a handheld vein locator device. However, the Dryden does not teach a transillumination device in which a clinician may use LEDs with differing wavelengths. Being able to use different wavelengths of light would be advantageous because different subcutaneous structures of the body absorb differing wavelengths of light. When light is absorbed by a structure, it will appear dark when compared to the rest of the tissue when using the transillumination technique. Thus, being able to switch between different wavelengths of light would enable a clinician to better visualize the associated subcutaneous structures.
U.S. Pat. Nos. 8,463,364 and 8,838,210 to Wood et al. both disclose similar vein locator devices. These devices scan a portion of a patient's body with ultraviolet and infrared light in order to produce a signal which is read by the device. The signal is processed through an algorithm in order to produce an image of the vasculature of the patient which is projected onto the skin of the patient. These devices do not allow a clinician to visualize the actual vasculature of a patient, but only images of the patient's vasculature projected onto the patient's skin. Furthermore, these devices don't allow a clinician to visualize other subcutaneous structures.
Thus, it would be advantageous to develop a transillumination device which is cheap and easy to manufacture, portable, allows a clinician to choose from different wavelengths of light, and allows a clinician to adjust the brightness intensity of device. The present invention fulfills these needs and provides other related advantages.